The present invention relates to an electrically driven brake booster equipped with an electrically driven actuator for generating a brake force.
A brake is controlled by an electrically driven actuator in accordance with a detected operation amount of a pedal and a detected position of the actuator. Used for detecting parameters for this control are, for example, a displacement sensor for detecting a displacement of a rod for operating a pedal or a brake piston, a rotation sensor for an electrically driven actuator, a hydraulic pressure sensor for detecting a hydraulic pressure for generating a brake force, a current sensor for detecting a current flowing through an electrically driven actuator, and the like. There is a problem that a control reference point in a brake non-operation state and a zero point of each parameter change because output values of a displacement sensor, a revolution sensor, a hydraulic sensor, and a current sensor change with variation and temperature characteristics of a sensor itself, variation and characteristics of a braking mechanism including an electrically driven actuator, and a sensor mount error.
JP-A-2007-1124226 (Patent Document 1) discloses an electrically driven brake booster.